Devices and methods of packaging semiconductor devices

ABSTRACT

Devices and methods of packaging semiconductor devices are disclosed. In some embodiments, a device includes a first semiconductor device and a second semiconductor device coupled to the first semiconductor device. An underfill material is disposed between the first semiconductor device and the second semiconductor device. The underfill material is also disposed on sidewalls of the first semiconductor device and the second semiconductor device. The underfill material has a first thickness on sidewalls of the first semiconductor device and a second thickness on sidewalls of the second semiconductor device. The second thickness is different than the first thickness.

PRIORITY CLAIM

This application is a divisional of U.S. patent application Ser. No. 14/584,741, filed on Dec. 29, 2014 and entitled “Devices and Methods of Packaging Semiconductor Devices,” which application is hereby incorporated herein by reference.

BACKGROUND

Semiconductor devices are used in a variety of electronic applications, such as personal computers, cell phones, digital cameras, and other electronic equipment. Semiconductor devices are typically fabricated by sequentially depositing insulating or dielectric layers, conductive layers, and semiconductive layers of material over a semiconductor substrate, and patterning the various material layers using lithography to form circuit components and elements thereon. Dozens or hundreds of integrated circuits are typically manufactured on a single semiconductor wafer. The individual dies are singulated by sawing the integrated circuits along scribe lines. The individual dies are then packaged separately, in multi-chip modules, or in other types of packaging.

The semiconductor industry has experienced rapid growth due to continuous improvement in the integration density of a variety of electronic components (e.g., transistors, diodes, resistors, capacitors, etc.). For the most part, this improvement in integration density has come from repeated reductions in minimum feature size (e.g., shrinking the semiconductor process node towards the sub-20 nm node), which allows more components to be integrated into a given area. As the demand for miniaturization, higher speed, and greater bandwidth, as well as lower power consumption and latency has grown recently, there has grown a need for smaller and more creative packaging techniques for semiconductor dies.

As semiconductor technologies further advance, stacked semiconductor devices, e.g., 3D integrated circuits (3DICs), have emerged as an effective alternative to further reduce the physical size of semiconductor devices. In a stacked semiconductor device, active circuits such as logic, memory, processor circuits, and the like are fabricated on different semiconductor wafers. Two or more semiconductor wafers may be installed or stacked on top of one another to further reduce the form factor of the semiconductor device. Package-on-package (PoP) devices are one type of 3DIC wherein dies are packaged and are then packaged together with another packaged die or dies.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It is noted that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

FIG. 1 through FIG. 3, FIG. 6 and FIG. 7 show cross-sectional views of a method of packaging semiconductor devices at various stages in accordance with some embodiments of the present disclosure.

FIG. 4 and FIG. 5 are perspective views of the semiconductor devices shown in FIG. 3 and FIG. 6, respectively, in accordance with some embodiments.

FIG. 8 through FIG. 13 illustrate cross-sectional views of a method of packaging semiconductor devices at various stages in accordance with some embodiments.

FIG. 14 through FIG. 18 illustrate cross-sectional views of a method of packaging semiconductor devices at various stages in accordance with some embodiments of the present disclosure.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.

Devices and methods of packaging semiconductor devices are disclosed in the present disclosure. Two semiconductor devices are coupled together and are partially singulated. An underfill material is disposed between the two semiconductor devices and along scribe lines. The two semiconductor devices are then fully singulated. The underfill material is left remaining on sidewalls of at least one of the semiconductor devices. The underfill material prevents or reduces chipping during the full singulation process and also prevents a saw blade from damaging the semiconductor devices during the full singulation process.

FIG. 1 through FIG. 3, FIG. 6 and FIG. 7 show cross-sectional views of a method of packaging semiconductor devices 100 a and 100 b at various stages in accordance with some embodiments of the present disclosure. FIG. 4 and FIG. 5 are perspective views of the semiconductor devices shown in FIG. 3 and FIG. 6, respectively.

Referring first to FIG. 1, a wafer 122 a is provided that includes a plurality of semiconductor devices 100 a formed thereon. The wafer 122 a is also referred to herein as a first wafer 122 a, for example. The semiconductor devices 100 a comprise fan-out structures in some embodiments. The semiconductor devices 100 a are also referred to herein, e.g., in the detailed description and in some of the claims, as first semiconductor devices 100 a or fan-out structures 100 a. The plurality of first semiconductor devices 100 a is in wafer form and is unsingulated. Only one first semiconductor device 100 a is shown in FIG. 1; however, dozens, hundreds, or more first semiconductor devices 100 a may be formed on the first wafer 122 a in an array of rows and columns (see FIG. 4).

Each of the first semiconductor devices 100 a comprises an integrated circuit die 102 a or a plurality of integrated circuit dies 102 a. The integrated circuit dies 102 a of the first semiconductor devices 100 a are also referred to herein as first integrated circuit dies 102 a.

The plurality of first semiconductor devices 100 a includes an interconnect structure 104 a that comprises a first redistribution layer (RDL) in some embodiments. The interconnect structure 104 a may also comprise other types of interconnect structures, such as a post passivation interconnect (PPI) structure, as an example. The first RDL 104 a comprises one or more insulating material layers and a plurality of conductive features formed in the insulating material layers, to be described further herein with reference to FIG. 12.

Referring again to FIG. 1, the plurality of first integrated circuit dies 102 a of the first wafer 122 a is coupled to the first RDL 104 a. The plurality of first integrated circuit dies 102 a may be coupled to contact pads or other conductive features of the first RDL 104 a, for example. The plurality of first integrated circuit dies 102 a is electrically coupled to portions of the first RDL 104 a, for example.

A plurality of through-vias 106 is also coupled to portions of the first RDL 104 a in some embodiments. The plurality of through-vias 106 provides vertical electrical connections for the plurality of first semiconductor devices 100 a, for example. In other embodiments, the plurality of through-vias 106 is not included.

A molding material 108 a is disposed around the plurality of first integrated circuit dies 102 a and around the plurality of through-vias 106, over the first RDL 104 a. The molding material 108 a comprises a molding compound comprised of an insulating material, such as an epoxy, a filler material, a stress release agent (SRA), an adhesion promoter, other materials, or combinations thereof, as examples.

An interconnect structure 104 b is disposed over the molding material 108 a, the plurality of first integrated circuit dies 102 a, and the plurality of through-vias 106. The interconnect structure 104 b comprises one or more conductive feature layers and one or more insulating material layers, as described for the first RDL 104 a. The interconnect structure 104 b comprises a second RDL 104 b in some embodiments. The first RDL 104 a and the second RDL 104 b provide horizontal electrical connections for the plurality of first semiconductor devices 100 a in some embodiments, for example.

The first semiconductor devices 100 a comprise a plurality of fan-out structures that include the first integrated circuit dies 102 a, the through-vias 106, the molding material 108 a, the RDLs 104 a and 104 b, and connectors 110 b coupled to the first RDLs 104 a in some embodiments, for example. Each of the first semiconductor devices 100 a may comprise one or more first integrated circuit dies 102 a in some embodiments, for example.

An example of a process flow for forming the first wafer 122 a that includes the plurality of first semiconductor devices 100 a will next be described. The plurality of first semiconductor devices 100 a may be formed by providing a carrier (not shown), and forming the first RDL 104 a over the carrier. The plurality of through-vias 106 may be formed over the first RDL 104 a by plating, photolithography, or other methods, before or after the plurality of first integrated circuit dies 102 a are coupled to the first RDL 104 a. In some embodiments, the plurality of through-vias 106 is plated over the first RDL 104 a, and the plurality of first integrated circuit dies 102 a is attached to the first RDL 104 a. The molding material 108 a is then deposited over the plurality of through-vias 106, the plurality of first integrated circuit dies 102 a, and exposed portions of the top surface of the first RDL 104 a. As deposited, the molding material 108 a may extend over top surfaces of the plurality of first integrated circuit dies 102 a and the plurality of through-vias 106. A chemical-mechanical polishing (CMP) process, a grinding process, an etch process, other methods, or a combination thereof is used to remove the molding material 108 a from over top surfaces of the plurality of first integrated circuit dies 102 a and the plurality of through-vias 106. A top portion of the plurality of through-vias 106 may also be removed in some embodiments, reducing their height or thickness. The second RDL 104 b is then formed over the molding material 108 a, the plurality of through-vias 106, and the plurality of first integrated circuit dies 102 a.

In another example of a process flow for forming the first wafer 122 a that includes the plurality of first semiconductor devices 100 a, a carrier (not shown) may be provided, and the second RDL 104 b is formed over the carrier. The plurality of through-vias 106 may be formed over the second RDL 104 b by plating, photolithography, or other methods, before or after the plurality of first integrated circuit dies 102 a is coupled to the second RDL 104 b. In some embodiments, the plurality of through-vias 106 is plated over the second RDL 104 b, and then the plurality of first integrated circuit dies 102 a is attached to the second RDL 104 b. The molding material 108 a is then deposited over the plurality of through-vias 106, the plurality of first integrated circuit dies 102 a, and exposed portions of the top surface of the second RDL 104 b. Any excess portions of molding material 108 a that extend over top surfaces of the plurality of first integrated circuit dies 102 a and the plurality of through-vias 106 is removed using a CMP process, a grinding process, an etch process, other methods, or a combination thereof. The first RDL 104 a is then formed over the molding material 108 a, the plurality of through-vias 106, and the plurality of first integrated circuit dies 102 a.

The process flow for forming the first wafer 122 a that includes the first semiconductor devices 100 a may also comprise other processing steps and orders of the processing steps. One or more carriers may be used to form the plurality of first semiconductor devices 100 a. At some point in the packaging process flow, openings are formed in an upper insulating material layer of the second RDL 104 b to expose contact pads of the second RDL 104 b. In some embodiments, a plurality of connectors 110 a, shown in phantom in FIG. 1 (e.g., in dashed lines), is formed in the openings over the contact pads of the second RDL 104 b. A connector 110 a is coupled to each of the exposed contact pads of the second RDL 104 b in some embodiments, for example. A plurality of connectors 110 b is also coupled to contact pads of the first RDL 104 a. The plurality of connectors 110 b may be arranged in a ball grid array (BGA) in some embodiments, for example. The material of the plurality of connectors 110 a and 110 b comprises a eutectic material such as solder that is adapted to melt at a predetermined temperature, for example. The connectors 110 a and 110 b may comprise solder balls or solder bumps, as examples. When the eutectic material cools, the plurality of connectors 110 a and 110 b can be used to electrically and mechanically couple the plurality of first semiconductor devices 100 a to another device or object.

The wafer 122 a that includes the plurality of first semiconductor devices 100 a is coupled to a first carrier 120 a, also shown in FIG. 1. In some embodiments, the first carrier 120 a comprises a carrier tape. The carrier tape 120 a may be coupled to a support, not shown. The plurality of connectors 110 b coupled to the first RDL 104 a of the plurality of first semiconductor devices 100 a is coupled to the first carrier 120 a in FIG. 1, for example. The first carrier 120 a may also comprise a carrier wafer or other type of carrier.

Referring next to FIG. 2, a plurality of semiconductor devices 100 b is provided and are coupled to a second carrier 120 b. The plurality of second semiconductor devices 100 b coupled to the second carrier 120 b effectively comprises a second wafer 122 b because of the attachment of the second semiconductor devices 100 b to the second carrier 120 b, for example. The plurality of semiconductor devices 100 b is also referred to herein as a plurality of second semiconductor devices 100 b.

The semiconductor devices 100 a are also referred to herein as second semiconductor devices 100 b, and the semiconductor devices 100 b are also referred to herein as first semiconductor devices 100 a, e.g., in some of the claims.

In some embodiments, the plurality of second semiconductor devices 100 b comprises and is referred to herein, e.g., in some of the claims, as a plurality of packaged semiconductor devices 100 b. The packaged semiconductor devices 100 b are fully packaged in some embodiments. In other embodiments, the packaged semiconductor devices 100 b may be partially packaged. For example, the packaged semiconductor device 100 b may include integrated circuit dies that have been encapsulated with protective materials, and electrical wiring structures may be coupled to the dies, to be described further herein. Further packaging will be performed on the second semiconductor devices 100 b in accordance with some embodiments of the present disclosure.

In some embodiments, a plurality of the second semiconductor devices 100 b is provided, and the plurality of second semiconductor devices 100 b is coupled to the second carrier 120 b by a method such as manually by an operator or technician, the use of an automated machine such as a pick-and-place machine, or other methods. The second semiconductor devices 100 b may be adhered to the second carrier 120 b using a die attached film (DAF), adhesive, or other materials (not shown). The second semiconductor devices 100 b are positioned on the second carrier 120 b to align with the first semiconductor devices 100 a of the first wafer 122 a in some embodiments, for example.

Each of the plurality of second semiconductor devices 100 b may comprise a substrate 112 that includes a plurality of contact pads disposed on. The substrate 112 may include one or more interconnect structures (not shown) formed thereon that provide horizontal connections for the plurality of second semiconductor devices 100 b in some embodiments. The substrate 112 may also include a plurality of through-vias (also not shown) formed therein. One or more integrated circuit dies 102 b may be coupled to a top surface of the substrate 112. Each of the plurality of second semiconductor devices 100 b comprises two vertically stacked integrated circuit dies 102 b in the embodiment shown in FIG. 2, for example. Two or more integrated circuit dies 102 b may also be packaged together horizontally in the second semiconductor devices in some embodiments, not shown.

In the embodiments shown, the integrated circuit dies 102 b are coupled to contact pads on a top surface of the substrate 112 by bond wires 114. The bond wires 114 and the through-vias provide vertical electrical connections for the plurality of second semiconductor devices 100 b in some embodiments, for example. A molding material 108 b is disposed over the integrated circuit dies 102 b, the bond wires 114, and the substrate 112. The molding material 108 b may comprise similar materials as described for the molding material 108 a of the plurality of first semiconductor devices 100 a, for example.

In some embodiments, the integrated circuit die 102 b or dies 102 b comprise dynamic random access memory (DRAM) devices, for example. The integrated circuit dies 102 b may also comprise other types of devices. One or more integrated circuit dies 102 b may be included in the second semiconductor device 100 b. The integrated circuit dies 102 b may be packaged together vertically as shown, or horizontally. The integrated circuit dies 102 b may be packaged in a wire bond type of package as shown in FIG. 2, or the integrated circuit dies 102 b may be packaged in other types of packages.

A plurality of connectors 110 c comprising a eutectic material is coupled to the bottom surface of the substrates 112 of the second semiconductor devices 100 b. The plurality of connectors 110 c may be coupled to contact pads on a bottom surface of the substrate 112, for example. In some embodiments, the plurality of second semiconductor devices 100 b does not include the plurality of connectors 110 c, e.g., in embodiments wherein the plurality of first semiconductor devices 100 a includes the plurality of connectors 110 a disposed on the top surface thereof (see FIG. 1). In other embodiments, both the plurality of connectors 110 a and the plurality of connectors 110 c are included on the first semiconductor devices 100 a and the second semiconductor devices 100 b, respectively. However, in the present disclosure, only the connectors 110 c on the substrate 112 of the plurality of second semiconductor devices 100 b are shown in the drawings.

In some embodiments, the second carrier 120 b comprises a carrier wafer. The second carrier 120 b may also comprise a carrier tape or other type of carrier, in other embodiments. The top surfaces of the plurality of second semiconductor devices 100 b are coupled to the second carrier 120 b. The molding material 108 b of the plurality of second semiconductor devices 100 b is coupled to the second carrier 120 b in FIG. 2, for example.

The effective second wafer 122 b (e.g., the second semiconductor devices 100 b coupled to the second carrier 120 b) is then coupled to the first wafer 122 a (e.g., to the first semiconductor devices 100 a on the first wafer 122 a) using the plurality of connectors 110 c (and/or 110 a; see FIG. 1), as shown in FIG. 3 through 6. A eutectic material of the connectors 100 c (and/or 110 a) is then reflowed, which mechanically and electrically couples the second semiconductor devices 100 b to the first semiconductor devices 100 a. Each of the plurality of second semiconductor devices 100 b is coupled to one of the plurality of first semiconductor devices 100 a using some of the plurality of connectors 110 c, for example. Because the plurality of second semiconductor devices 100 b is advantageously effectively in a wafer form (e.g., by being coupled to the second carrier 120 b), improved alignment of the plurality of second semiconductor devices 100 b with the plurality of first semiconductor devices 100 a (which are unsingulated and are also in wafer form), is achieved.

Note that all of the elements of the plurality of first semiconductor devices 100 a and the plurality of second semiconductor devices 100 b are not labeled in FIG. 3 and some of the subsequent figures of the present disclosure, in order to simplify the drawings: FIGS. 1 and 2 can be referred to again for more detailed element numbers. Furthermore, FIGS. 12 and 17 include a majority of the element numbers shown in FIGS. 1 and 2, and also include some additional labeled elements that will be explained further herein.

FIG. 4 is a perspective view illustrating a method of coupling the effective second wafer 122 b to the first wafer 122 a in accordance with some embodiments. Alignment marks 116 b of the effective second wafer 122 b are aligned with alignment marks 116 a of the first wafer 122 a during the coupling together of the effective second wafer 122 b with the first wafer 122 a in some embodiments. The effective second wafer 122 b coupled to the first wafer 122 a is shown in FIG. 5 in a perspective view.

FIGS. 4 and 5 illustrate that the plurality of first semiconductor devices 100 a of the first wafer 122 a and the plurality of second semiconductor devices 100 b of the effective second wafer 122 b are arranged in an array of rows and columns. A plurality of scribe lines 124 a and 124 b resides between adjacent second semiconductor devices 100 b, as shown in FIG. 5. Scribe lines 124 a are disposed in a y direction, and scribe lines 124 b are disposed in an x direction that is substantially perpendicular to the y direction. Only one scribe line 124 b in the x direction is shown for simplicity in FIG. 5; however, a scribe line 124 b resides between each of the adjacent second semiconductor devices 100 b. The scribe lines 124 a and 124 b are referred to collectively herein as scribe lines 124. Although not visible in the view shown in FIG. 5, the first wafer 122 a also includes a plurality of scribe lines 124 disposed between adjacent first semiconductor devices 100 a in the x and y direction. The scribe lines 124 of the first semiconductor devices 100 a and the scribe lines 124 of the second semiconductor devices 100 b are substantially aligned in some embodiments, for example.

Next, in some embodiments, the second carrier 120 b is removed as shown in FIG. 7 in a cross-sectional view, and the plurality of first semiconductor devices 100 a and the plurality of second semiconductor devices 100 b that are coupled together are singulated to form a plurality of packaged semiconductor devices 140, as shown in FIGS. 8 through 13. In other embodiments, the first carrier 120 a is removed, and the plurality of first semiconductor devices 100 a and the plurality of second semiconductor devices 100 b that are coupled together are singulated to form a plurality of packaged semiconductor devices 140, as shown in FIGS. 14 through 18.

A method of packaging semiconductor devices in accordance with some embodiments will next be described with reference to FIGS. 8 through 13. After the effective second wafer 122 b including the plurality of second semiconductor devices 100 b coupled to the second carrier 120 b is coupled to the first wafer 122 a coupled to the first carrier 120 a as shown in FIG. 8, the second carrier 120 b is removed (see FIGS. 7 and 9). The coupled plurality of second semiconductor devices 100 b and plurality of first semiconductor devices 100 a (e.g., the coupled-together plurality of second semiconductor devices 100 b and plurality of first semiconductor devices 100 a) are partially singulated along the scribe lines 124 disposed between adjacent ones of the plurality of second semiconductor devices 100 b and adjacent ones of the plurality of first semiconductor devices 100 a, as shown in FIG. 9. The coupled plurality of second semiconductor devices 100 b and plurality of first semiconductor devices 100 a are partially singulated using a saw 127. The saw 127 may comprise a diamond blade or other materials in some embodiments, for example. The saw 127 includes a saw blade 126 having a first width comprising dimension w₁, wherein dimension w₁ comprises about 120 μm to about 300 μm in some embodiments. Dimension w₁ comprises about 120 μm to about 180 μm, about 180 μm to about 220 μm, and/or about 220 μm to about 300 μm in some embodiments, for example. Dimension w₁ may also comprise other values. The saw blade 126 is also referred to herein, e.g., in some of the claims, as a first saw blade 126.

The second semiconductor devices 100 b are already spaced apart at the scribe lines 124. The second semiconductor devices 100 b were spaced apart at the scribe lines 124 when they were attached to the second carrier 120 b, as shown in FIG. 2, for example. The first wafer 122 a that includes the plurality of first semiconductor devices 100 b is partially singulated by the saw 127, resulting in the plurality of first semiconductor devices 100 a being partially singulated, as illustrated in FIG. 9. In accordance with some embodiments, the saw 127 forms recesses 128 in the first wafer 122 a between each of the plurality of first semiconductor devices 100 a.

Next, an underfill material 130 is disposed between the coupled plurality of second semiconductor devices 100 b and plurality of first semiconductor devices 100 a and along the scribe lines 124, as shown in FIG. 10. The underfill material 130 comprises similar materials as described for the molding material 108 a of the plurality of first semiconductor devices 100 a in some embodiments. In some embodiments, the underfill material 130 comprises benzoic alcohol, epoxy resin, silica, and/or other materials, as examples. The underfill material 130 is applied to the tops and/or sides of the coupled plurality of second semiconductor devices 100 b and plurality of first semiconductor devices 100 a.

The underfill material 130 is applied using an underfill material 130 dispensing tool or system in some embodiments. The underfill material 130 can be applied using auger technology and a dispensing valve, as examples. Applying the underfill material 130 in some embodiments comprises steps such as preheating the first and second semiconductor devices 100 a and 100 b to a predetermined temperature, visually aligning to the first and second semiconductor devices 100 a and 100 b, locating a surface of the first and second semiconductor devices 100 a and 100 b upon which to dispense the underfill material 130, dispensing a fill pass which may comprise a single pass or multiple passes, dispensing one or more fillet passes, and/or post-heating the first and second semiconductor devices 100 a and 100 b, as examples. Other tools, methods, and/or steps may also be used to form the underfill material 130.

In some embodiments, the underfill material 130 is a liquid when applied so that it flows between and around the plurality of connectors 110 c between the plurality of second semiconductor devices 100 b and the plurality of first semiconductor devices 100 a. The underfill material 130 is then cured or allowed to dry so that it forms a solid. Due to a meniscus effect, the underfill material 130 may retract away from the top surfaces of the plurality of second semiconductor devices 100 b during the curing or drying process, as shown in FIG. 10. In other embodiments, the underfill material 130 does not retract and substantially reaches the top surfaces of the second semiconductor devices 100 b, as shown in FIG. 15.

Referring next to FIG. 11, the coupled plurality of second semiconductor devices 100 b and plurality of first semiconductor devices 100 a are then fully singulating along the scribe lines 124 to form a plurality of packaged semiconductor devices 140. The singulation is performed with a saw 127′ comprising a similar saw as saw 127 shown in FIG. 9. However, in some embodiments, the saw 127′ comprises a saw blade 126′ having a smaller width than the saw blade 126 of saw 127 so that a predetermined amount of the underfill material 130 is left remaining on sidewalls of the plurality of second semiconductor devices 100 b and an upper portion of sidewalls of the plurality of first semiconductor devices 100 a. The saw blade 126′ of saw 127′ comprises a second width comprising dimension w₂, wherein dimension w₂ comprises about 80 μm to about 260 μm in some embodiments. Dimension w₂ comprises about 80 μm to about 120 μm, about 120 μm to about 200 μm, and/or about 200 μm to about 280 μm in some embodiments, for example. Dimension w₂ may also comprise other values. The saw blade 126′ is also referred to herein, e.g., in some of the claims, as a second saw blade 126′. The second width w₂ of the second saw blade 126′ is less than the first width w₁ of the first saw blade 126 in some embodiments, for example.

FIG. 12 is a cross-sectional view of the packaged semiconductor devices 140 shown in FIG. 11 that illustrates some dimensions and relative dimensions of the plurality of packaged semiconductor devices 140 disposed on the first carrier 120 a after the full singulation process. The partial singulation width after the partial singulation step shown in FIG. 9 comprises a dimension d₁, wherein dimension d₁ comprises about 160 μm to about 340 μm in some embodiments. Dimension d₁ comprises about 160 μm to about 220 μm, about 220 μm to about 280 μm, and/or about 280 μm to about 340 μm in some embodiments, for example. Dimension d₁ is substantially the same as or slightly larger than dimension w₁, the first width of the first saw blade 126 used for the partial singulation in some embodiments, for example. The final singulation width after the full singulation step shown in FIG. 7 comprises a dimension d₂, wherein dimension d₂ comprises about 120 μm to about 300 μm in some embodiments. Dimension d₂ comprises about 120 μm to about 180 μm, about 180 μm to about 240 μm, and/or about 240 μm to about 300 μm in some embodiments, for example. Dimension d₂ is substantially the same as or slightly larger than dimension w₂, the second width of the second saw blade 126′ used for the full singulation in some embodiments, for example. In some embodiments, dimension d₁ comprises dimension d₂+2*(20 μm). Dimension d₁ is greater than dimension d₂ by about 20 μm on each side in some embodiments, for example. Dimensions d₁ and d₂ may also comprise other values and other relative values.

The distance between an edge of the partial singulation cut to an edge of the first semiconductor device 100 a comprises a dimension d₃, wherein dimension d₃ comprises about 20 μm to about 50 μm in some embodiments. Dimension d₃ comprises about 20 μm to about 30 μm, about 30 μm to about 40 μm, and/or about 40 μm to about 50 μm in some embodiments, for example. The second semiconductor device 100 b is fully singulated (e.g., the underfill material 130 between the second semiconductor devices 100 b is fully singulated along the scribe lines 124), and the first semiconductor device 100 a is partially singulated by an amount comprising a dimension d₄, wherein dimension d₄ comprises about 25 μm to about 60 μm in some embodiments. Dimension d₄ comprises about 25 μm to about 40 μm, about 40 μm to about 50 μm, and/or about 50 μm to about 60 μm in some embodiments, for example. A thickness of the first integrated circuit dies 102 a comprises a dimension d₅, wherein dimension d₅ comprises about 100 μm to about 200 μm in some embodiments. Dimension d₅ comprises about 100 μm to about 130 μm, about 130 μm to about 165 μm, and/or about 165 μm to about 200 μm in some embodiments, for example. The die attach film 103 comprises a thickness of about 10 μm to about 20 μm. Dimension d₄ comprises about ¼ *(d₅+the thickness of the die attach film 103) in some embodiments, for example. Dimension d₄ also comprises a length (e.g., in a vertical direction in FIG. 12) of the sidewalls of the first semiconductor devices 100 a that is covered by the underfill material 130. A thickness of the underfill material 130 disposed on the sidewalls of the first semiconductor devices 100 a comprises a dimension d₆, wherein dimension d₆ comprises a thickness of about 5 μm to about 20 μm in some embodiments. Dimension d₆ comprises about 5 μm to about 10 μm, about 10 μm to about 15 μm, and/or about 15 μm to about 20 μm, for example. A thickness of the underfill material 130 disposed on the sidewalls of the second semiconductor devices 100 b comprises a dimension d₇, wherein dimension d₇ comprises a thickness of about 5 μm to about 100 μm in some embodiments. Dimension d₇ comprises about 5 μm to about 35 μm, about 35 μm to about 90 μm, and/or about 90 μm to about 100 μm, for example. These values for dimensions d₆ and d₇ of the underfill material 130 are sufficient to provide adequate protection for the packaged semiconductor devices 140 during the full singulation process, for example. In embodiments wherein the second semiconductor devices 100 b comprise a smaller width than the first semiconductor devices 100 a, dimension d₇ is greater than dimension d₆. The first semiconductor devices 100 a comprise a thickness comprising dimension d₈. In some embodiments, dimension d₄ is about 50% or greater than dimension d₈, for example. In other words, the underfill material 130 is disposed on sidewalls of the first semiconductor devices 100 a by about 50% or greater of a thickness comprising dimension d₈ of the first semiconductor devices 100 a, in some embodiments. This amount of underfill material 130 is sufficient to provide adequate protection for the packaged semiconductor devices 140 during the full singulation process, for example. Dimensions d₃, d₄, d₅, d₆, d₇, and d₈ may also comprise other values and other relative values.

FIG. 12 also illustrates some additional elements of the plurality of first semiconductor devices 100 a and the plurality of second semiconductor devices 100 b. The first RDL 104 a of the first semiconductor devices 100 a comprises a plurality of insulating material layers 142 a and a plurality of conductive features 144, 146, and 148 a formed within or on the plurality of insulating material layers 142 a. The insulating material layers 142 a may comprise silicon dioxide, low dielectric constant (k) materials having a k value less than silicon dioxide, passivation materials, other insulating materials, or multiple layers or combinations thereof, as examples. The conductive features 144, 146, and 148 a of the first RDL 104 a may comprise conductive lines 144, conductive vias 146, and/or contact pads 148 a that are comprised of copper, copper alloys, or other materials, as examples. The connectors 110 b are coupled to the contact pads 148 a of the first RDL 104 a. The first integrated circuit dies 102 a include a plurality of contact pads 148 b that is coupled to portions of the first RDL 104 a.

The second RDL 104 b of the first semiconductor devices 100 a also includes a plurality of insulating material layers 142 b and a plurality of contact pads 148 c formed therein. The contact pads 148 c may comprise an under-ball metallization (UBM) structure or other types of structures. The connectors 110 c are coupled to the contact pads 148 c of the second RDL 104 b.

The substrate 112 of the second semiconductor devices 100 b includes contact pads 148 d disposed on a bottom surface thereof that are coupled to the connectors 110 c. The substrate 112 also includes contact pads 148 e on a top surface thereof that the bond wires 114 are coupled to.

After the full singulation process shown in FIG. 11, the first carrier 120 a is removed, as shown in FIG. 13. The plurality of packaged semiconductor devices 140 may then be coupled to another device or object using the plurality of connectors 110 b disposed on the bottom surfaces of the packaged semiconductor devices 140, e.g., using a surface mount technology (SMT) process.

FIG. 13 also illustrates some additional dimensions of portions of the packaged semiconductor devices 140. An overlap of a second integrated circuit die 102 b to a first integrated circuit die 102 a comprises a dimension d₉, wherein dimension d₉ comprises about 5 μm to about 500 μm in some embodiments. Dimension d₉ comprises about 5 μm to about 20 μm, about 20 μm to about 100 μm, and/or about 100 μm to about 500 μm in some embodiments, for example. An overlap of a largest one of the second integrated circuit dies 102 b to the first integrated circuit die 102 a comprises dimension d₉ in the embodiments shown, for example. In embodiments wherein the second integrated circuit dies 102 b comprise DRAM devices, dimension d₉ comprises the overlap of the first integrated circuit die 102 a and the DRAM device 102 b. The overlap comprising dimension d₉ comprises a distance from an edge of the first integrated circuit die 102 a to an edge of the DRAM device 102 b, for example. Dimension d₉ may also comprise other dimensions.

Likewise, an overlap of a first semiconductor device 100 a to a second semiconductor device 100 b may comprise a dimension d₁₀, wherein dimension d₁₀ comprises about 5 μm to about 500 μm in some embodiments. Dimension d₁₀ comprises about 5 μm to about 10 μm, about 10 μm to about 20 μm, about 20 μm to about 450 μm, and/or about 450 μm to about 500 μm in some embodiments, for example. Dimension d₁₀ shown in FIG. 13 may also comprise other dimensions. The overlap between the semiconductor devices 100 a and 100 b comprising dimension d₁₀ results from the semiconductor devices 100 a and 100 b comprising different widths, for example.

In some embodiments, grooves 142 are formed in sidewalls of the underfill material 130 during the full singulation process. The grooves 142 are formed by the saw blade 126′ of the saw 127′ during the full singulation process shown in FIG. 11, for example. The grooves 142 comprise a roughness formed on the surface of the sidewalls of the underfill material 130. The grooves 142 may extend along the length of the sidewalls and may comprise a depth within the sidewalls of the underfill material 130 (e.g., in a horizontal direction in the view shown in FIG. 13) by an amount comprising dimension d₁₁. Dimension d₁₁ is substantially the same as dimension d₆ in some embodiments. For example, the grooves 142 have a depth of dimension d₁₁ within substantially an entire thickness comprising dimension d₆ of the underfill material 130 on sidewalls of an upper portion of the first semiconductor devices 100 a in some of the embodiments shown in FIG. 13. In other embodiments, dimension d₁₁ may be less than dimension d₆ of the thickness of the underfill material 130 on the sidewalls of the upper portion of the first semiconductor devices 100 a. Dimension d₁₁ may also comprise other values and other relative values.

In the embodiments shown in FIGS. 8 through 13, the underfill material 130 is formed on sidewalls of the first semiconductor devices 100 a and on sidewalls of an upper portion of the second semiconductor devices 100 b.

In other embodiments, the underfill material 130 may be completely formed on sidewalls of both the first semiconductor devices 100 a and the second semiconductor devices 100 b, as shown in FIGS. 14 through 18, which illustrate cross-sectional views of a method of packaging semiconductor devices at various stages in accordance with some embodiments of the present disclosure. Beginning with the packaging process stage shown in FIG. 8, the first carrier 120 a is removed, and the second carrier 120 b coupled to the plurality of second semiconductor devices 100 b is inverted, as shown in FIG. 14.

After the first carrier 120 a is removed, the coupled plurality of second semiconductor devices 100 b and plurality of first semiconductor devices 100 a are partially singulated along the scribe lines 124 disposed between adjacent ones of the plurality of second semiconductor devices 100 b and adjacent ones of the plurality of first semiconductor devices 100 a, as shown in FIG. 14. The coupled plurality of second semiconductor devices 100 b and plurality of first semiconductor devices 100 a are partially singulated using a saw 127 comprising a first saw blade 126 having a width comprising dimension w₁.

The first wafer 122 a that includes the plurality of first semiconductor devices 100 b is fully singulated by the saw 127. In accordance with some embodiments, the first saw blade 126 reaches the spaces between the first wafer 122 a and the second wafer 122 b so that the underfill material 130 shown in FIG. 10 can be applied around the plurality of connectors 110 c. The effective second wafer 122 b that includes the plurality of second semiconductor devices 100 b is not singulated in some embodiments during the partial singulation process. Because the second semiconductor devices 100 b are individually attached to the second carrier 120 b, the second semiconductor devices 100 b are already separated at the scribe lines 124, for example. In other embodiments, the second semiconductor devices 100 b may be partially singulated by the saw 127, not shown. For example, if the second semiconductor devices 100 b are attached to the second carrier 120 b such that the spacing between adjacent second semiconductor devices 100 b along the scribe lines 124 is less than the width w₁ of the first saw blade 126, portions of the second semiconductor devices 100 b may be removed during the partial singulation process.

Next, an underfill material 130 is disposed between the coupled plurality of second semiconductor devices 100 b and plurality of first semiconductor devices 100 a and along the scribe lines 124, as shown in FIG. 15, and as described with reference to FIG. 10. The coupled plurality of second semiconductor devices 100 b and plurality of first semiconductor devices 100 a are then fully singulating along the scribe lines 124 to form a plurality of packaged semiconductor devices 140, as shown in FIG. 16 and as described with reference to FIG. 11. The full singulation process is performed with a saw 127′ that comprises a second saw blade 126′ that has a smaller second width comprising dimension w₂ than the first width comprising dimension w₁ of the first saw blade 126 of saw 127, so that a predetermined amount of underfill material 130 is left remaining on sidewalls of the plurality of first semiconductor devices 100 a and on sidewalls of the plurality of second semiconductor devices 100 b.

FIG. 17 is a cross-sectional view of the packaged semiconductor devices 140 shown in FIG. 16, illustrating some additional elements of the plurality of first semiconductor devices 100 a and the plurality of second semiconductor devices 100 b and some dimensions and relative dimensions of the packaged semiconductor devices 140 disposed on the first carrier 120 a after the full singulation process, as shown and described for FIG. 12. Dimensions d₁, d₂, d₃, d₉, d₁₀, and d₁₁ comprise similar values as described for dimensions d₁, d₂, d₃, d₉, d₁₀, and d₁₁ shown in FIGS. 12 and 13 in some embodiments. However, dimension d₇ in FIG. 17 is less than dimension d₇ shown in FIGS. 12 and 13, and dimension d₆ in FIG. 17 is greater than dimension d₆ shown in FIGS. 12 and 13 in some embodiments. For example, in FIG. 17, a thickness of the underfill material 130 disposed on the sidewalls of the first semiconductor devices 100 a comprises a dimension d₆, wherein dimension d₆ comprises a thickness of about 5 μm to about 100 μm in some embodiments. Dimension d₆ comprises about 5 μm to about 35 μm, about 35 μm to about 90 μm, and/or about 90 μm to about 100 μm in some embodiments, for example. A thickness of the underfill material 130 disposed on the sidewalls of the second semiconductor devices 100 b comprises a dimension d₇, wherein dimension d₇ comprises a thickness of about 5 μm to about 20 μm in some embodiments. Dimension d₇ comprises about 5 μm to about 10 μm, about 10 μm to about 15 μm, and/or about 15 μm to about 20 μm, for example. These values for dimensions d₆ and d₇ of the underfill material 130 are sufficient to provide adequate protection for the packaged semiconductor devices 140 during the full singulation process, for example. In embodiments wherein the first semiconductor devices 100 a comprise a smaller width than the second semiconductor devices 100 b, dimension d₇ is less than dimension d₆.

In the embodiments shown in FIG. 17, an overlap of a second semiconductor device 100 b to a first semiconductor device 100 a that results from the semiconductor devices 100 a and 100 b comprising different widths may comprise a dimension d₁₀, wherein dimension d₁₀ comprises about 5 μm to about 500 μm in some embodiments. Dimension d₁₀ comprises about 5 μm to about 10 μm, about 10 μm to about 20 μm, about 20 μm to about 450 μm, and/or about 450 μm to about 500 μm in some embodiments, for example. Dimension d₁₀ shown in FIG. 17 may also comprise other values.

The molding material 130 is left remaining on sidewalls of each of the plurality of first semiconductor devices 100 a and also on sidewalls of each of the second semiconductor devices 100 b. Thus, the molding material 130 may be formed on substantially the entire length of the sidewalls of both the first semiconductor devices 100 a and the second semiconductor devices 100 b in some embodiments, for example, as shown in FIG. 17.

After the full singulation process, the second carrier 120 b is removed, as shown in FIG. 18. The plurality of packaged semiconductor devices 140 may then be coupled to another device or object using the connectors 110 b, e.g., using a SMT process. As described for FIG. 13, the integrated circuit dies 102 a and 102 b may comprise an overlap comprising dimension d₉, and the semiconductor devices 100 a and 100 b may comprise an overlap comprising dimension d₁₀, within the packaged semiconductor devices 140, in some embodiments. Grooves 142 having a depth comprising dimension d₁₁ within the sidewalls of the underfill material are formed in the sidewalls of the underfill material 130 by the saw blade 126′ during the full singulation process shown in FIG. 14. Dimension d₁₁ is substantially the same as dimension d₇ in some embodiments. For example, the grooves 142 have a depth of dimension d₁₁ within substantially an entire thickness comprising dimension d₇ of the underfill material 130 on sidewalls of the second semiconductor devices 100 b in some of the embodiments shown in FIG. 17. In other embodiments, dimension d₁₁ may be less than dimension d₇ of the thickness of the underfill material 130 on the sidewalls of the second semiconductor devices 100 b.

Embodiments of the present disclosure are advantageously implementable in and are particularly beneficial when used in package-on-package (PoP) devices, in some applications. The packaged semiconductor devices 140 may comprise PoP devices or system-on-a chip (SOC) devices in some embodiments, as examples.

In some embodiments, the first integrated circuit dies 102 a comprise logic devices or processors and the first semiconductor devices 100 a comprise fan-out wiring, and the second integrated circuit dies 102 b comprise memory devices such as dynamic random access memory (DRAM) devices, e.g., in some embodiments wherein the two-step singulation and underfill material application process described herein is implemented in an integration fan-out (InFO) PoP device. In some embodiments, the second semiconductor devices 100 b include a plurality of stacked integrated circuit dies 102 b comprising DRAM devices, for example. The first integrated circuit dies 102 a, the second integrated circuit dies 102 b, the first semiconductor devices 100 a, and the second semiconductor devices 100 b may also comprise other types of devices, and the two-step singulation and underfill material application processes described herein may be implemented in other types of applications.

Advantages of some embodiments of the present disclosure include providing novel packaging methods for PoP devices and other types of 3DICs wherein a two-step singulation approach is implemented. The underfill material applied after the first partial singulation step advantageously results in the prevention or reduction of sidewall chipping during the full singulation process; thus, packaging yields are improved. The packaging methods described herein require fewer processing steps and result in higher accuracy. Because the second semiconductor devices are effectively in wafer form because the second semiconductor devices are attached to the second carrier when they are connected to or coupled to the first semiconductor devices that are also in wafer form, alignment is improved, which results in less chance of the dicing saw blade hitting edges of the semiconductor devices during the singulation process and causing damage. The “batch mount” (e.g., effective wafer to wafer attachment) provides improved alignment for the singulation process. The packaging processes described herein also result in a time and cost savings. The batch mount avoids the need to individually attach each one of the second semiconductor devices to the wafer containing the first semiconductor devices, for example. Furthermore, the packaging methods and structures described herein are easily implementable in packaging process flows and structures.

In some embodiments, a device includes a first semiconductor device and a second semiconductor device coupled to the first semiconductor device. An underfill material is disposed between the first semiconductor device and the second semiconductor device. The underfill material is also disposed on sidewalls of the first semiconductor device and the second semiconductor device. The underfill material comprises a first thickness on sidewalls of the first semiconductor device and a second thickness on sidewalls of the second semiconductor device. The second thickness is different than the first thickness.

In other embodiments, a device includes a fan-out structure and a packaged semiconductor device coupled to the fan-out structure by a plurality of connectors. An underfill material is disposed between the fan-out structure and the packaged semiconductor device and between the plurality of connectors. The underfill material is also disposed on sidewalls of the fan-out structure and sidewalls of the packaged semiconductor device.

In yet other embodiments, a method of packaging a semiconductor device includes providing a fan-out structure, coupling a packaged semiconductor device to the fan-out structure using a plurality of connectors, and partially singulating the coupled packaged semiconductor device and fan-out structure along scribe lines disposed proximate sidewalls of the packaged semiconductor device and sidewalls of the fan-out structure. An underfill material is disposed between the packaged semiconductor device and the fan-out structure and along the scribe lines. The method includes fully singulating the coupled packaged semiconductor device and fan-out structure along the scribe lines to form a packaged semiconductor device.

Another embodiment is a device including a semiconductor device having bottom-side connectors. It also includes a fan-out structure having top-side connectors, a semiconductor die, molding material, and a plurality of through vias through the molding material. The molding material encapsulates the semiconductor die and forms sidewalls of the semiconductor device. The molding material also has a stepped side profile. The top-side connectors of the fan-out structure are coupled to the bottom-side connectors of the semiconductor device. An underfill material is placed around the top-side connectors and on sidewalls of the fan-out structure and on the sidewalls of the semiconductor device. The underfill material also fil.s the stepped side profile of the molding material.

The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure. 

What is claimed is:
 1. A device, comprising: a fan-out structure, the fan-out structure comprising a molding compound forming sidewalls of the fan-out structure, wherein the molding compound has a stepped sidewall profile; a packaged semiconductor device coupled to the fan-out structure by a plurality of connectors; and an underfill material disposed between the fan-out structure and the packaged semiconductor device and between the plurality of connectors, wherein the underfill material is also disposed on sidewalls of the fan-out structure and sidewalls of the packaged semiconductor device, wherein the underfill material fills the stepped sidewall profile of the molding compound, wherein a sidewall of the packaged semiconductor device comprising the underfill material is perpendicular to a top surface of the packaged semiconductor device.
 2. The device according to claim 1, wherein the fan-out structure comprises a first redistribution layer (RDL), an integrated circuit die coupled to the first RDL, a plurality of through-vias coupled to the first RDL, a molding material disposed over the first RDL around the integrated circuit die and the plurality of through-vias, and a second RDL disposed over the integrated circuit die, the plurality of through-vias, and the molding material.
 3. The device according to claim 2, wherein the packaged semiconductor device comprises a dynamic random access memory (DRAM) device disposed over a substrate, and a molding compound disposed over the DRAM device and the substrate.
 4. The device according to claim 3, wherein an overlap of the integrated circuit die and the DRAM device comprises about 5 μm to about 500 μm, and wherein the overlap comprises a distance from an edge of the integrated circuit die to an edge of the DRAM device.
 5. The device according to claim 1, wherein a portion of the underfill material disposed on the sidewalls of the packaged semiconductor device has a first uniform sidewall thickness and a portion of the underfill material disposed on the sidewalls of the fan-out structure has a second uniform sidewall thickness.
 6. The device according to claim 5, wherein the second uniform sidewall thickness is thicker than the first uniform sidewall thickness.
 7. A device, comprising: a first semiconductor device comprising a first surface and a second surface opposite the first surface, the second surface comprising a first plurality of connectors; a second semiconductor device comprising a third surface and a fourth surface opposite the third surface, the third surface comprising a first plurality of contact pads, wherein the first plurality of contact pads of the second semiconductor device are coupled to the first plurality of connectors of the first semiconductor device; and an underfill material disposed between the first semiconductor device and the second semiconductor device, wherein the underfill material is also disposed on sidewalls of the first semiconductor device and the second semiconductor device, wherein the underfill material comprises a first uniform lateral thickness on sidewalls of the first semiconductor device, wherein the underfill material comprises a second uniform lateral thickness on sidewalls of the second semiconductor device, wherein the second uniform lateral thickness is different than the first uniform lateral thickness, and wherein a first surface of the underfill material is level with the first surface of the first semiconductor device.
 8. The device according to claim 7, wherein the first uniform lateral thickness comprises about 5 μm to about 20 μm, or wherein the second uniform lateral thickness comprises about 5 μm to about 100 μm.
 9. The device according to claim 8, wherein the first semiconductor device comprises a fan-out structure and wherein the second semiconductor device comprises a packaged semiconductor device.
 10. The device according to claim 9, wherein the fan-out structure comprises a first redistribution layer (RDL), an integrated circuit die coupled to the first RDL, a plurality of through-vias coupled to the first RDL, a molding material disposed over the first RDL around the integrated circuit die and the plurality of through-vias, and a second RDL disposed over the integrated circuit die, the plurality of through-vias, and the molding material.
 11. The device according to claim 7, wherein sidewalls of the underfill material comprise a plurality of grooves.
 12. The device according to claim 11, wherein the plurality of grooves comprises a depth within the sidewalls of the underfill material of about 5 μm to about 100 μm or less.
 13. The device according to claim 7, wherein the underfill material laterally encapsulates the first semiconductor device and second semiconductor device, and wherein a second surface of the underfill material opposite the first surface does not extend beyond the fourth surface of the second semiconductor device.
 14. A device, comprising: a semiconductor device comprising bottom-side connectors; a fan-out structure comprising top-side connectors, a semiconductor die, molding material, and a plurality of through-vias through the molding material, the molding material encapsulating the fan-out structure and forming sidewalls of the fan-out structure, wherein the molding material has a stepped side profile, wherein the top-side connectors are coupled to the bottom-side connectors; and an underfill material disposed around the top-side connectors and on sidewalls of the fan-out structure and on the sidewalls of the semiconductor device, the underfill material filling the stepped side profile of the molding material.
 15. The device according to claim 14, wherein the stepped side profile is about 25 μm to about 60 μm tall, and wherein the stepped side profile is about 5 μm to about 20 μm deep.
 16. The device according to claim 14, wherein a thickness of the underfill material disposed on the sidewalls of the semiconductor device is about 5 μm to about 100 μm.
 17. The device according to claim 16, wherein the thickness of the underfill material disposed on the sidewalls of the semiconductor device is tapered to be smaller at a top portion of the sidewall underfill material and larger toward a bottom portion of the sidewall underfill material.
 18. The device according to claim 14, further comprising a carrier and an adjacent packaged device spaced a uniform distance, the uniform distance corresponding to a width of a singulation saw blade.
 19. The device according to claim 14, wherein the fan-out structure further comprises a first redistribution layer (RDL), the semiconductor die coupled to the first RDL, the plurality of through-vias coupled to the first RDL, and a second RDL disposed over the semiconductor die, the plurality of through-vias, and the molding material.
 20. The device according to claim 19, wherein the semiconductor device comprises a dynamic random access memory (DRAM) device disposed over a substrate, and a molding compound disposed over the DRAM device and the substrate. 